Hot top



March 3, 1931. EGLER 1,794,840

HOT TOP Filed Oct. 26 192 INVEINTOR wn-m-zs s Patented Mar. 3, 1931UNITED STATES PATENT OFFICE NIIKLAS I. EGLER, OF MONESSEN, PENNSYLVANIA,ASSIGNOR TO INSULATED TOP COMPANY, 01 PITTSBURGH, PENNSYLVANIA, ACORPORATION OF DELAWARE HOT TOP Application filed October 26, 1928.Serial No. 815,308.

My invention relates to improvements in hot-tops for ingot molds, andthe object of my invention is the overcoming of disadvantages otherwiseincident to the use of hot-tops such as are now commonly in use.

The invention is illustrated in the accompanying drawings, in which Fig.I is a view in plan and Fig. II a view in vertical section of thehot-top of my invention in place on the ingot mold.

Hot-tops such as are commonly used are molded and hardened bodies ofrefractory material, of such external size and shape as to be arrangedwithin and to protrude from the open upper end of the ingot mold. Thisgeneral arrangement of the hot-top in the'mouth of the ingot mold isillustrated in the drawings. The ingot mold is indicated by the numeral1, and the hot-top by 2.

Refractory hot-tops cannot be made to minutely accurate size. Incidentalto the drying and burning, to which a refracto hottop must in itsmanufacture be'sub ected,.

there is shrinkage which is so far variable and irregular that, as a.practical matter, the average hot-top is somewhat under size, and there'1s an undesired but unavoidable space. at

which the hot-top when'set in the mouth of the mold stands away from themold wall. In consequence the operation of curing must accommodateitself. When the ody o-f molten metal rising within the mold cavity.reaches the lower 'edge of the hot-top, the

operation of pouring is arrested, and an interval of time. is allowed toensue, during which the metal in contact with or adjacent to thehot-topat its lower end grows colder and approaches solidification. Thenwhen presently pouring is renewed and the molten metal rises in thehot-top the tendency of-the metal to .run into and .to rise within suchspace as may exist between hot-top and mold wall is prevented andovercome. The development of a fin at that point is guarded against.

My invention consists in a heat-absorbing body arranged within the moldcavity at the lower end of the introduced'hot-top and formin in effect aportion of or an extension of the ot-top, whlch body-so absorbing heatfrom the body of molten metal has the effect which in the practice abovedescribed is accom lished by an intermission of the operation ofpouring. The operation of pouring may be continued without intermissionto the end, and the fin-forming tendency described is to an appreciableand practically adequate degree vented.

Such a heat-absorbing body is in the drawguarded against and preingsindicated at 3. It will conveniently be Y formed of metal, preferably ofcast iron or cast steel. It will be an endless band or ring of the shapeand size of the mold cavity and of bulk suflici'ent to accomplish theend desired. Preferably it is formedas a separate member sustainedinplace within the mouth of the mold, conveniently by hooks l which takover the rim of the mold. It is of such wi th as to form a rest orsupport for the hot-top, and of such thickness as to act as a chill, inthe manner described. Ordinarily,

it is from 2 to 4 inches wide and an inch thick.

. The dimensions are given by way of example,

merely. The body 3 being formed of cast metal, may be formed much moreaccurately to size than is possible in the forming of the refractoryhot-top. Thespace interval'be- I in. the mouth of the mold and sustainedin position by its hooks. The hot-top is then placed upon it, in theposition indicated. The pouring of the metal into the mold so preparedis continued without intermission to the end, and during the pouring thechill is efiective in the manner described. The adjacent metal is bycontact with it so far chilled that fin formatlon in the narrow spaceinterval between-hot-top and mold wall is to -a practical degreeprevented and overcome.

fin-preventing chill-ring of cast iron ar ranged Within the mold cavityadjacent the upper end thereof and extending in continuity around theentire inner Wall of the cavity, and a preformed hot-top of refractorymaterial resting upon said r1ng.

2. In combination with an ingot mold a fin-preventing chill-ring of castiron arranged Within the mold cavity adjacent the upper end thereof andextending in continuity around the entire inner Wall of the cavity,together With means engaging the upper rim of the mold for suspendingsaid ring in place, and a preformed hot-top of refractorymaterial'resting upon said ring.

In testimony whereof, I have hereunto set my hand.

NIKLAS F. EGLER.

